Improvement in knob-latches



H. 10N ES.

Knob-Latches.

No. 146,910. Patentedlamz'inszm;

JMW.'

UNITED STATES HENRY JONES, OF PORTLAND, MAINE.

IMPROVEMENT lN KNOB-LATCHEKS.

Specification forming part of Letters Patent No. 146,910, dated January 27, 1874; application filed February 27, 1873.

To all whom it may concern Y Be it known that I, HENRY J oNEs, of Portland, in the county of Cumberland and State of Maine, have invented certain new and useful Improvements in Latches 5 and I do hereby declare that the following is a full, clear, and exact description thereof, that will enable others skilled in the art to which it appertains to make and use the same, reference being had to the accompanying drawings and to the letters of reference marked thereon, which form a part of this specification.

Figure l is a face view, with the back plate removed to show the working parts. Fig. 2 is a detailed view of one of the tumblers which are located over the key-bolt.

Same letters show like parts.

My invention relates to certain improvements in door-latches. lts object is to provide such an arrangement of springs, a cam, and a pivoted arm, together witlrthe hub of the knob-shank, that the bolt will be easily pushed back into the case when the door is pushed into the jamb, or is shut, in consequence of one only of the springs being bent, and by the operation of both the springs, in connection with the other devices named, to insure the return of the bolt to itsoriginal position after being drawn or turned in by the knob.

a is the latch-bolt; b, the key-bolt; c, the short cylinder, having the socket d to receive the shank of the knob. c e is a cam attached to the cylinder. j" is an arm, turning on the pivot g, and kept pressed against the cam c c by the spring h, which is also attached to the pivot y. i is the easy spring ofthe latclrbolt, and is also attached to the pivot g. j is a dog, turning' on the pivot k, and kept pressed down on the top edge oi' the key-bolt I) by the spring lpressing against the spring m, and also attached to the dog at n.. o isa shoulder on the latch-bolt, and p a projection on the kcy-bolt. The. projection p pushes the dog j upward, so that its edge q moves up behind the shoulder o, and thus keys or locks the latch-bolt wheneverthe key-bolt is thrown. r is afinger on the key-bolt; s, a shoulder on the lower` arm or bifurcation of the latch-bolt. The finger pushes out the latch-bolt to the full extent of its proper movement whenever the key-bolt is thrown, and this insures the perfect operation of the dog j and shoulder o. t indicates the position of the keyhole in the back plate ofthe lock, or where the key is inserted when the lock is to be operated from the outside of a room. the key. The key-hole u is the keyhole to he used when the lock is operated from the inside of a room. Thus the key, when inserted from the inside, cannot be reached from the outside except by cutting through the back plate of the lock. The key-bolt bis thrown by the key bit onpoint, lifting the tumblers 'o w, and allowing the stud x to move through y the slot y, and in'to the recess z, as the bolt b is pushed by the key. The key, when inserted into the hole a, can only be turned one way, the guard a preventing any other movement. Vhen the bolt is thrown, the bit of the key rests upon the part b of the guard a', and at the same time its outer edge pushes or rests against the shoulder or point c on the keybolt, thus securing the bolt in that position when thrown, and rendering it necessary to cut through the back plate of the lock and turn back the key before the bolts can be moved from the outside ot' the room.

A description of the general operation ot my invention may thus be given.

By turning the shank of the knob that is intended to enter the socket d, the following op erations take place: The two springs L and i must be contracted, and their united force has the tendency to force out the bolt a when the power is removedi'roin the knob. Thus the latch-bolt o is rendered quite certain in its operation, and also to resume its position. When a door is shut without turning the knob-that is, pushed into the jamb-the spring t', pressvving against'the pin j", is the only spring to be bent. Thus the door can be easily shut, as the latch is easily sprung. This arrangement and operation of these two springs is of great importance to the convenient and reliable op eration of a latch of this kind. The easy spring t' admits of the door being sluit when pushed into the jamb wit-hout slamming the two to.- gctlier. h and c force the latch-bolt out again when drawn in by the turning of the knob.

lVheu the key-bolt is thrown, the following i 'movements take place: The finger r travels The recess t is to receive the end ofl up to the shoulder' s, and, if the bolt uy is not fully thrown forward, pushes it forward to the full extent of its movement. The projection p :forces the do g j up behind the shoulder 0. The bit of the key, When the locking is done from the inside, lies upon b', and the edge of the bit presses against c.

It will be seen that the two springs i h are formed of one and the same piece of metal, and so arranged as to operate in the manner described-that is, the eas5r spring to operate by itself, as set forth, and the two to operate together, as described.

'hat I ela-im as my invention, and desire to secure by Letters Patent, is-

The combination of the arm f with the e51- inder e, eam ,e e', springs z' h, pivot g, pin f, and the latch-bolt a, all to operate as described.

In testimony that I claim the foregoing` I have hereunto set my hand.

HENRY J ONES.

Witnesses WM. HENRY CLIFFORD, FRANK H. J ORDAN. Y 

